We were lucky with the Highest One- he was out of communication with his kin, if he had any, and in all the cases we've seen so far- even if the world had space travel, everyone thought each orb was a unique entity, rather than a piece of a greater whole.

I've asked Viveca the same question, and she's given me the same assurances- and I do think the station is safe, save for infiltration through- or by- one of the crew. But that doesn't rule out other forces realizing there are multiple orbs, and seeking them out.